Many many blank domains


I use to have a perfectly working pi-Hole config but since about 1 week ago I noticed that my home router is sending a lot of request to it :


All these requests are empty/blank.
Restarted the router but it keeps requesting…

A pihole -t give me this :

Jun  2 23:09:36 dnsmasq[22978]: query[A] . from
Jun  2 23:09:36 dnsmasq[22978]: cached . is NODATA-IPv4
Jun  2 23:09:36 dnsmasq[22978]: query[AAAA] . from
Jun  2 23:09:36 dnsmasq[22978]: cached . is NODATA-IPv6

My /etc/hosts has been edited on pi but should be clean.
Any idea on what it could be ?
Seems to be the same problem as s97t9t5f but no answer.

I did not change anything on these two devices lately expect regular update.
My config is a pi 3 running Diet-pi with unbound & pi-Hole and a Synology RT2600ac router, everything up to date.

Thanks, Sushi

Just for clarification, your home router is a Synology 2600RT ?

Queries to “empty” (technically .) are legit, they are just a bit … meaningless in this context. I assume it is a router bug introduced by a recent update.


I am observing the same activity, and also have a Synology 2600 router.

As already said, empty queries are not forbidden, they are just not very meaningful IMO. This is something you should request to get resolved by Synology.